Tow stretcher



R. A. BRAND! TOW STRETGHER Aug. 16, 1966 5 Sheets-Sheet l Filed Dec. 19. 2

ATTORNEY R. A. BRAND] TOW STRETCHER Aug. 16, 1966 5 Sheets-Sheet 2 Filed Dec. 19, 1962 INVEN TOR. R/CHA/PD A. BRA/VD/ QQJZOK M ATTORNEY Aug. 16, 1966 Filed Dec. 19, 1962 5 Sheets-Sheet 5 INVENTOR. RICHARD A. ERA/VD/ ATTORNEY R. A. BRAND! TOW STRETCHER Aug. 16, 1966 Filed Dec. 19.

5 Sheets-Sheet 4 INVENTOR. RICHARD A. e/m/vo/ aodm f ATTORNEY Aug. 16, 1966 R. A. BRANDI 3,266,082

TOW STRETCHER Filed Dec. 19. 1962 5 Sheets-Sheet 5 INVENTOR.

1L lP/QlA/PD A. BRA/VD/ flaw/#42041 ATTORNEY United States Patent 3 2665982 TOW STRETCHER Richard A. Brandi, Bridgeport, Pa., assignor to Hepion,

Inc, West Conshohocken, Pa.,-a corporation of Pennsylvania Filed Dec. 19, 1%2, Ser. No. 245,887 6 Claims. (CI. 18-1) This invention relates to a tow stretcher, and more particularly, to apparatus and method for stretching synthetic filaments such as nylon so as to impart desirable characteristics to the filaments.

It is well known that many of the synthetic fibers attain their desirable characteristics by imparting a stretch thereto. Depending upon the denier of the filaments, nylon should be stretched from between four and seven times its original length so as to impart to it the desirable characteristics generally associated with nylon. A substantial number of filaments is referred to as a tow. Apparatus for stretching a tow of filaments is called a tow stretcher. The tow stretcher of the present invention, for example, is designed to stretch a tow having up to 500,000 filaments.

It has been proposed heretofore to stretch a nylon tow by subjecting the tow to a plurality of rollers rotatably driven at different speeds which increase in the direction of the travel of the tow. I have found that such devices suffer from a plurality of disadvantages which are overcome by the present invention.

Hence, the devices proposed heretofore control the amount of stretch by accurately controlling and varying the surface speeds of the various rollers with which the tow is in surface contact. Such devices required accurate, expensive variable speed motors with delicate devices to adjust the speed of the motors. Such devices require constant maintenance and attention to assure that the various rollers are rotating at the required speed.

In accordance with the present invention, the tow is subjected to a predetermined amount of stretch by causing the tow to pass over a plurality of rollers which are rotating at speeds which increase in the direction of the travel of the tow. However, each of the speed rollers is coupled to a single constant speed motor by known mechanical coupling elements. The use of a single constant speed motor substantially reduces the cost of a tow stretcher and materially reduces the maintenance necessary to assure that the predetermined amount of stretch is being imparted to the tow. Such predetermined amount of stretch is the approximate amount of stretch for the smallest denier of the filaments. When it is desired to stretch filaments of higher denier, or filaments of a different synthetic resin, additional stretch may be imparted to the tow by subjecting the tow to a controlled amount of frictional drag.

Hence, the present invention contemplates one set of speed rollers for approximating the amount of stretch which must be imparted to a tow and a second means such as drag rollers for imparting the difference in stretch between the approximated amount and the necessary amount as dictated by the nature of the filament. Since the present invention contemplates constant speed motors and a simple positive means for imparting frictional drag, positive assurance is had that the proper amount of stretch is being imparted to the filaments of the tow.

It is an object of the present invention to provide a novel apparatus and method for stretching filaments of synthetic yarns.

It is another object of the present invention to provide a novel apparatus and method for stretching and crimping nylon filaments.

It is another object of the present invention to provide a novel apparatus and method for stretching syn- 3,266,032 Patented August 16, 1966 thetic filaments which is simpler, cheaper, and more relia'ble'to operate and maintain than those proposed heretofore.

It is still another object of the present invention to provide a novel apparatus and method for stretching a synthetic filament by increasing the amount of stretch from a predetermined amount to a desired amount by subjecting the filaments to a controlled amount of frictional drag.

Other objects will appear hereinafter.

For the purpose of illustrating the present invention there is shown in the drawings forms which are presently preferred; it being understood, however, that this invention is not limited to the precise arrangements and instrumentaliti'es shown.

FIGURE 1A is a side elevation view of the lefthand end of the apparatus of the present invention.

FIGURE 1B is a side elevation view of the righthand end of the apparatus of the present invention.

FIGURE 2A is a top plan view of the apparatus illustrated in FIGURE 1A.

FIGURE 2B is a top plan view of the apparatus illustrated in FIGURE 2A.

FIGURE 3 is a sectional view taken along the lines 33 in FIGURE 2A.

FIGURE 4 is a sectional view taken along the lines 44 in FIGURE 13.

FIGURE 5 is a partial perspective view of a yoke shown at the lefthand end of FIGURE 3.

FIGURE 6 is a side elevation view of the support for a drag roller shown on an enlarged scale and partly broken away for purposes of illustration.

Referring to the drawing in detail, wherein like numerals indicate like elements, there is shown in FIG- URES 1A and 118 a tow stretcher and crimper designated generally as 10.

The apparatus 10 includes a creel stand 12 which rotatably supports a large number of creels 14 on opposite sides thereof, see FIGURES 1B and 4. The creels 14 have cheese wound thereon. Cheese is the term generally associated with unstretched raw synthetic filaments such as nylon. The filaments of cheese are drawn from the inner end of the creels 14 and caused to pass through one of a plurality of holes 18 in a filament guide 16.

The apparatus 10 includes a frame designated generally as 24. The frame 24 includes a pair of horizontally disposed spaced parallel top rails 20 and 20' and similar bottom rails 22 and 22'. The filament guide 16 is supported by the bottom rails 22 and 22'.

The rails 20, 20', 22 and 22' rotatably support a plurality of drag rollers 3040. While only six such drag rollers are illustrated, a greater or lesser number may be provided as desired. It will be noted that the drag rollers are in a staggered relationship as shown more clearly in FIGURE 1B. Each of the drag rollers and their respective supports are identical, hence only drag roller 40 will be described in detail.

The drag roller 46 is a cylindrical drum having a standard smooth finish such as a or finish. The axle 42 of roller 40/ is supported by bearing 44 which is removably secured to the rail 20. The axle 42 is provided with a longitudinally extending peripheral groove 48 adapted to receive the end of a bolt 46 depending on the position of the bolt 46. The bolt 46 may be in the nature of a setscrew, is threadedly engaged with the bearing 44 and may have a position wherein one end thereof is disposed within the groove 48 and may have another position wherein the axle 42 is freely rotatable in the bearing at its opposite ends. Hence, each of the drag rollers is selectively locked or freely rotatable.

The frame 24 rotatab'ly supports a pair of speed rollers 50 and 54, one above the other, to the left of the drag rollers. Roller 50 is provided with an axle 52 rotatably supported in a bearing on the frame 24. Roller 54 is provided with an axle 56 rotatably supported in bearings on the frame 24. As will be made clear hereinafter, the rollers 501and 54 arerotatably driven at a constant speed and these rollers may be referred to'hereinafter as a. first set of speed rollers.

As shown more clearly in FIGURES 1A and 2B, rollers 58 and 62 are rotatably supported one above the other by the frame 24. Roller 58 is provided with an axle 60 rotatably supported at its ends by the frame 24. Roller 62 is provided with an axle 64 rotatably supported at its ends by the frame 24. As will be made clear hereinafter, the rollers 58 and 62 are rotatably driven at a constant speed and may be referred to as a second set of speed rollers.

As shown more clearly in FIGURES 1A and 2A, rollers 66 and 70 are rotatably supported one above the other by the frame 24. Roller 66 is provided with an axle 68 rotatably supported at its ends by the frame 24. Roller 70 is provided with an axle 72 rotatably supported at its ends by the frame 24. As will be made clear hereinafter, the rollers 68 and 70 are rotatably driven at a constant speed and may be referred to as a third set of speed rollers.

The apparatus is provided with a single constant speed motor 74, see FIGURES 1A and 2B. The motor 74 is provided with a pulley on its output shaft coupled to the pulley of a speed reducer 78 by a plurality of belts 76. The speed reducer 78 is provided with a sprocket on its output shaft which is coupled to a similar sprocket on axle 72 of roller 70 by means of chain 82. The free end of axle 72 as shown more clearly in FIG- URES 2A is supported by hearing 80. In this manner, roller 70 may be rotatably driven by motor 74 at a constant speed such as 650 feet per minute. A second sprocket is provided on aXle 72 and coupled to a larger sprocket on axle 64 of roller 62 by means of chain 84. Due to the relationship between the size of the sprockets, roller 64 will be driven at a lower constant speed such as 550 feet per minute.

Another sprocket is coupled to axle 64 and in turn is coupled to a substantially larger sprocket 88 on axle 56 by means of chain 86. Hence, roller 54 will be rotatably driven at a constant lower speed such as 150 feet per minute.

The axles for rollers 50 and 54 are mechanically coupled by a set of gears 90 so that these rollers rotate in opposite directions at the same rate of speed. Likewise, the rollers 58 and 62 will rotate at the same rate of speed in opposite directions by means of the coupling of the axles for these rollers by a set of gears 92. Also, the axles for rollers 66 and 70 are rotatably coupled by a set of gears 94 so that these rollers rotate in opposite directions at the same rate of speed. Hence, it will be seen that each of the first, second and third sets of speed rollers will be rotatably driven by a single motor at constant speeds with the rate of speed increasing in the direction of movement of the tow.

As shown more clearly in FIGURE 2A, a pulley 96 on axle 68 is operatively coupled to a pulley on shaft 100 by means of a plurality of pulley belts 88. As shown more clearly in FIGURE 1A, the shaft 100 extends transversely across the frame 24 and is rotatably supported at its ends by bearings. A pulley 102 on the shaft 100 is operatively coupled to pulley 106 of a crimper designated generally as 103 by means of pulley belt 104. Pulley 106 is secured to a transversely extending shaft 108.

A pulley 110 on shaft 108 is operatively coupled to a pulley 112 by means of belt 116. Pulley 112 is secured to a shaft 114 rotatably supported at its free ends by frame 105 of the crimper 103. Shaft 108 is likewise supported by the frame 105. A roller 118 is secured to the shaft 114. A roller 124 is rotatably supported below the roller 118 as shown more clearly in FIGURE 4 3. The rotary movement of the shaft 114 is coupled to the roller 124 by means of a pair of meshing gears 120 and 122. Hence, the rollers 118 and 124 rotate at the same rate of speed in opposite directions.

As shown more clearly in FIGURES 2A and 3, a pulley 126 is provided on shaft 108 and operatively coupled to pulley 128 on shaft 130 by belt 132. Shaft 130 is rotatably supported by the frame 105 and has secured thereto a nip roller 134. The nip roller 134 is adapted to be moved toward and away from a second nip roller 136 on shaft 138 by means of an actuator 135. The nip rollers 134 and 136 will pull the tow through the apparatus 10 from the creels 14 and over the various rollers discussed above. Due to the mechanical coupling and the ratio between the various pulleys, the nip rollers 134 and 136 will rotate at a constant speed which is higher than any of the above mentioned speeds such as 1200 feet per minute. A funnel 137 is disposed between the nip rollers and roller 124 as shown more clearly in FIGURES 2A and 3.

The nip rollers 134 and 136 are caused to move in opposite directions at the same rate of speed as a result of meshing gears 140 on each of the shafts 130 and 138. A sprocket 142 is provided at one end of the shaft 138. Sprocket 142 is coupled to a sprocket 144 on shaft 148 by means of chain 146. Shaft 148 is rotatably supported at its ends by the frame 105. A second shaft 154 is rotatably supported at its ends by frame 105 and parallel to shaft 148. The shafts 148 and 154 are each horizontally disposed.

Shafts 148 and 154 support a second set of nip rollers 150 and 152, respectively. Shafts 148 and 154 rotate at the same rate of speed in opposite directions due to the meshing engagement between gears 156 and 158 which are shown more clearly in FIGURE 2A. A yoke 162 as shown more clearly in FIGURES 3 and 5 is supported above the plane of the shafts 148 and 154. An apertured plate 164 is provided below the yoke 162 and above the plane of the shafts 148 and 154. Shaft 154 is provided with an actuator adapted to move the said shaft toward and away from shaft 148 as desired.

' A crimp box 166 is provided directly below the plane of the shafts 148 and 154 and has its inlet in line with the aperture in plate 164. The crimp box 166 is a simple means for imparting a crimp to the tow thereby effecting the physical properties of the filaments of the tow. A container 168 such as a'barrel may be provided below the outlet port of the crimp box 166 to receive the crimped stretched tow of synthetic filaments. If desired, other means for receiving and collecting the crimped tow may be provided in place of the barrel.

The operation of the apparatus and method of the present invention is as follows:

Let it be assumed that the drag rollers are provided with a normal smooth finish and have a diameter of approximately twelve inches. Also, it will be assumed that the creels 14 have wound thereon 3 denier nylon filaments. The filaments will be gathered from the innermost end of the creels 14 and fed through the holes 18, around the idler roller 28 and then around the drag rollers 30-40 in that order. Between the idler roller 28 and the funnel 37, the tow will be in the form of a sheet or layer as it passes over the various rollers.

From the drag roller 40, the tow passes around the three sets of speed rollers. While passing over the three sets of speed rollers, the variation in the surface speed of the speed rollers which progresses in the direction of travel of the tow causes the tow to be stretched a predetermined amount which will only approximate the desired amount of stretch which must be imparted to the material. The difference between the approximate amount and the necessary amount of stretch will be effected by unlocking one or more of the drag rollers 30-40 thereby varying the frictional drag on the tow.

As the denier of the filaments increases, an increasing number of the drag rollers 30-40 must be locked by aligning the groove in the axle with the bolt in the bearing and threading the bolt with respect to its bearing so that it enters the groove in the drag roller axle. For example, only drag roller 40 may be locked while operating the apparatus with 3 denier filaments. Depending upon the number of drag rollers utilized, the surface finish of the drag rollers, the diameter of the drag rollers and the type of filaments being stretched, anyone skilled in the art may easily ascertain by simple tests the number of drag rollers which must be locked as a function of the denier of the filaments. Hence, the only maintenance required with the present invention is to lock the proper number of drag rollers depending upon the denier and type of filaments.

The stretched tow passes from the third set of speed rollers around the guide rollers 118 and 124 and is then grouped in the form of a rope by passing through funnel 137. From funnel 137, the tow passes through the nip rollers 134 and 136 which in conjunction with nip rollers 150 and 152 do the actual unwinding of the cheese from the creels and pulling the same through the various rollers described above. From the nip rollers 150 and 152, the tow passes through the crimp box 166 Where a crimp is imparted thereto. Thereafter, the crimped stretched tow is collected in a container such as barrel 168.

If the next run will be made with the same type of filament but a higher denier, the only change which need be made is to lock one or more of the drag rollers depending upon the denier of the filaments for the next run. Since all of the speed rollers and the nip rollers are mechanically driven from a constant speed motor, maintenance and adjustments are practically nil as compared with the devices proposed heretofore. Also, it will be appreciated that the present invention may be converted from one type of filament to another or from one denier of a filament to another denier substantially faster than the devices proposed heretofore.

The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof and, accordingly, reference should be made to the appended claims, rather than to the foregoing specification as indicating the scope of the invention.

I claim:

1. A stretching apparatus adapted to be disposed between creels of unstretched filaments and a crimper comprising a frame, a first set of speed rollers extending transversely across the frame, a single motor operatively coupled to said speed rollers to rotate said rollers at different speeds with the speed of rotation of the rollers increasing in the direction of intended travel of filaments, and said frame rotatably supporting a plurality of drag rollers extending transversely across the frame, each of said drag rollers being freely rotatable, and means for selectively locking at least one of said drag rollers with respect to said frame said drag rollers being positioned so that they contact the filaments before the filaments contact the speed rollers.

2. Apparatus for stretching filaments comprising a first means for stretching filaments including a plurality of freely rotatable drag rollers, means for selectively locking at least one of said drag rollers, and a second means for stretching filaments a predetermined amount subsequent to the stretching of the filaments by the first means, said second means including a plurality of rollers adapted to be rotated at different speeds increasing in the direction of travel of the filaments and with which the filaments will serially contact the same, and each of said first and second means being continuously operable.

3. Apparatus comprising means for supporting creels of cheese, drag rollers for selectively imparting a frictional drag on a tow of said cheese, a plurality of speed rollers, means for rotating said speed rollers at dilferent speeds, means for pulling the tow around a portion of said drag rollers and then around a portion of said speed rollers, said pulling means including rotatably mounted nip rollers, said means for rotating said speed rollers including a constant speed motor operatively coupled to said speed rollers by mechanical members, means coupling said roller to said nip rollers in a manner so that said nip rollers may rotate at a speed higher than the highest speed of said speed rollers, and means for selectively locking some of said drag rollers to prevent rotation of the same.

4. Apparatus in accordance with claim 3 wherein said drag rollers are disposed between the creel supporting means and the speed rollers.

5. Apparatus comprising means for supporting creels of cheese, at least two sets of drag rollers for selectively imparting a frictional drag on a tow of said cheese, each set of drag rollers including an upper and a lower roller mounted for rotation about a substantially fixed axis, means for selectively preventing some of said drag rollers from rotating freely, a plurality of speed rollers supported for rotation about a substantially fixed axis, motor means coupled to said speed rollers for rotating said speed rollers at different speeds increasing in the direction of travel of the tow, and means for pulling the tow around a portion of said drag rollers and then around said portion of said speed rollers.

6. Apparatus for stretching filaments comprising a first means for stretching filaments including a plurality of idler drag rollers, mounted for rotation about their longitudinal axes by contact with the filaments to be stretched, means for selectively preventing free rotation of at least some of said idler drag rollers thereby imparting frictional drag on said filaments, and a second means for stretching filaments a predetermined amount subsequent to the stretching of the filaments by the first means, said second means including a plurality of rollers adapted to be rotated at different speeds increasing in the direction of travel of the filaments and with which the filaments will serially contact the same and each of said first and second means being continuously operable, and means for pulling said filaments over and around said idler drag rollers and said speed rollers.

References Cited by the Examiner UNITED STATES PATENTS 1,981,351 11/1934 Etzkorn. 2,016,391 10/1935 Riley et al. 2,123,936 7/1938 Dreyfus et a1. 2,289,232 7/ 1942 Babcock 264290 2,757,433 8/1956 Lenk 28-713 FOREIGN PATENTS 514,874 7/1955 Canada.

624,011 7/ 1961 Canada.

630,665 11/1961 Canada.

443,076 2/1936 Great Britain.

687,212 2/1953 Great Britain.

60,426 1/ 1948 Netherlands.

ALEXANDER H. BRODMERKEL, Primary Examiner.

A. L. LEAVITT, F. S. WHISENHUNT,

Assistant Examiners. 

2. APPARATUS FOR STRETCHING FILAMENTS COMPRISING A FIRST MEANS FOR STRETCHING FILAMENTS INCLUDING A PLURALITY OF FREELY ROTATABLE DRAG ROLLERS, MEANS FOR SELECTIVELY LOCKING AT LEAST ONE OF SAID DRAG ROLLERS, AND A SECOND MEANS FOR STRETCHING FILAMENTS A PREDETERMINED AMOUNT SUBSEQUENT TO THE STRETCHING OF THE FILAMENTS BY THE FIRST MEANS, SAID SECOND MEANS INCLUDING A PLURALITY OF ROLLERS ADAPTED TO BE ROTATED AT DIFFERENT SPEEDS INCREASING IN THE DIRECTION OF TRAVEL OF THE FILAMENTS AND WITH WHICH THE FILAMENTS WILL SERIALLY CONTACT THE SAME, AND EACH OF SAID FIRST AND SECOND MEANS BEING CONTINUOUSLY OPERABLE. 